[github-182] Fix root property size calculation. Thanks to netmackan. This closes #182

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1878721 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 271 insertions, 188 deletions

diff --git a/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java b/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java
index 069ebc0292..c381c517ab 100644
--- a/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java
+++ b/src/java/org/apache/poi/poifs/filesystem/POIFSMiniStore.java
@@ -252,7 +252,7 @@ public class POIFSMiniStore extends BlockStore
           if (!sbat.hasFreeSectors()) {
               blocksUsed += _filesystem.getBigBlockSizeDetails().getBATEntriesPerBlock();
           } else {
-              blocksUsed += sbat.getUsedSectors(false);
+              blocksUsed += sbat.getOccupiedSize();
           }
        }
        // Set the size on the root in terms of the number of SBAT blocks
diff --git a/src/java/org/apache/poi/poifs/storage/BATBlock.java b/src/java/org/apache/poi/poifs/storage/BATBlock.java
index 4a2f3f3b8f..9ef00ad1f5 100644
--- a/src/java/org/apache/poi/poifs/storage/BATBlock.java
+++ b/src/java/org/apache/poi/poifs/storage/BATBlock.java
@@ -192,6 +192,27 @@ public final class BATBlock implements BlockWritable {
         return usedSectors;
     }
 
+    /**
+     * How much of this block is occupied?.
+     * This counts the number of sectors up and including the last used sector.
+     * Note that this is different from {@link #getUsedSectors(boolean)} which
+     * could be smaller as it does not count unused sectors where there are
+     * used ones after it (i.e. fragmentation).
+     *
+     * @since POI 5.0.0
+     */
+    public int getOccupiedSize() {
+        int usedSectors = _values.length;
+        for (int k = _values.length - 1; k >= 0; k--) {
+            if(_values[k] == POIFSConstants.UNUSED_BLOCK) {
+                usedSectors--;
+            } else {
+                break;
+            }
+        }
+        return usedSectors;
+    }
+
     public int getValueAt(int relativeOffset) {
        if(relativeOffset >= _values.length) {
           throw new ArrayIndexOutOfBoundsException(
@@ -201,6 +222,7 @@ public final class BATBlock implements BlockWritable {
        }
        return _values[relativeOffset];
     }
+
     public void setValueAt(int relativeOffset, int value) {
        int oldValue = _values[relativeOffset];
        _values[relativeOffset] = value;
@@ -221,6 +243,7 @@ public final class BATBlock implements BlockWritable {
     public void setOurBlockIndex(int index) {
        this.ourBlockIndex = index;
     }
+
     /**
      * Retrieve where in the file we live
      */
@@ -237,7 +260,6 @@ public final class BATBlock implements BlockWritable {
      * @exception IOException on problems writing to the specified
      *            stream
      */
-
     public void writeBlocks(final OutputStream stream) throws IOException {
         // Save it out
         stream.write( serialize() );
diff --git a/src/testcases/org/apache/poi/poifs/storage/TestBATBlock.java b/src/testcases/org/apache/poi/poifs/storage/TestBATBlock.java
index 72afb0346b..10689b2e21 100644
--- a/src/testcases/org/apache/poi/poifs/storage/TestBATBlock.java
+++ b/src/testcases/org/apache/poi/poifs/storage/TestBATBlock.java
@@ -37,7 +37,7 @@ public final class TestBATBlock {
 
     @Test
     public void testEntriesPerBlock() {
-        assertEquals(128, POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS.getBATEntriesPerBlock()); 
+        assertEquals(128, POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS.getBATEntriesPerBlock());
     }
 
     @Test
@@ -52,81 +52,81 @@ public final class TestBATBlock {
 
     @Test
     public void testCalculateMaximumSize() {
-       // Zero fat blocks isn't technically valid, but it'd be header only
-       assertEquals(
-             512, 
-             BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 0)
-       );
-       assertEquals(
-             4096, 
-             BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 0)
-       );
-       
-       // A single FAT block can address 128/1024 blocks
-       assertEquals(
-             512 + 512*128, 
-             BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 1)
-       );
-       assertEquals(
-             4096 + 4096*1024, 
-             BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 1)
-       );
-       
-       assertEquals(
-             512 + 4*512*128, 
-             BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 4)
-       );
-       assertEquals(
-             4096 + 4*4096*1024, 
-             BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 4)
-       );
-       
-       // One XBAT block holds 127/1023 individual BAT blocks, so they can address
-       //  a fairly hefty amount of space themselves
-       // However, the BATs continue as before
-       assertEquals(
-             512 + 109*512*128, 
-             BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 109)
-       );
-       assertEquals(
-             4096 + 109*4096*1024, 
-             BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 109)
-       );
-             
-       assertEquals(
-             512 + 110*512*128, 
-             BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 110)
-       );
-       assertEquals(
-             4096 + 110*4096*1024, 
-             BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 110)
-       );
-       
-       assertEquals(
-             512 + 112*512*128, 
-             BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 112)
-       );
-       assertEquals(
-             4096 + 112*4096*1024, 
-             BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 112)
-       );
-       
-       // Check for >2gb, which we only support via a File
-       assertEquals(
-               512 + 8030L *512*128,
-               BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 8030)
-       );
-       assertEquals(
-               4096 + 8030L *4096*1024,
-               BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 8030)
-       );
+        // Zero fat blocks isn't technically valid, but it'd be header only
+        assertEquals(
+                512,
+                BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 0)
+        );
+        assertEquals(
+                4096,
+                BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 0)
+        );
+
+        // A single FAT block can address 128/1024 blocks
+        assertEquals(
+                512 + 512 * 128,
+                BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 1)
+        );
+        assertEquals(
+                4096 + 4096 * 1024,
+                BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 1)
+        );
+
+        assertEquals(
+                512 + 4 * 512 * 128,
+                BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 4)
+        );
+        assertEquals(
+                4096 + 4 * 4096 * 1024,
+                BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 4)
+        );
+
+        // One XBAT block holds 127/1023 individual BAT blocks, so they can address
+        //  a fairly hefty amount of space themselves
+        // However, the BATs continue as before
+        assertEquals(
+                512 + 109 * 512 * 128,
+                BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 109)
+        );
+        assertEquals(
+                4096 + 109 * 4096 * 1024,
+                BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 109)
+        );
+
+        assertEquals(
+                512 + 110 * 512 * 128,
+                BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 110)
+        );
+        assertEquals(
+                4096 + 110 * 4096 * 1024,
+                BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 110)
+        );
+
+        assertEquals(
+                512 + 112 * 512 * 128,
+                BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 112)
+        );
+        assertEquals(
+                4096 + 112 * 4096 * 1024,
+                BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 112)
+        );
+
+        // Check for >2gb, which we only support via a File
+        assertEquals(
+                512 + 8030L * 512 * 128,
+                BATBlock.calculateMaximumSize(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS, 8030)
+        );
+        assertEquals(
+                4096 + 8030L * 4096 * 1024,
+                BATBlock.calculateMaximumSize(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS, 8030)
+        );
     }
 
     @Test
     public void testUsedSectors() {
         POIFSBigBlockSize b512 = POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS;
         POIFSBigBlockSize b4096 = POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS;
-        
+
         // Try first with 512 block sizes, which can hold 128 entries
         BATBlock block512 = BATBlock.createEmptyBATBlock(b512, false);
         assertTrue(block512.hasFreeSectors());
@@ -138,36 +138,36 @@ public final class TestBATBlock {
         block512.setValueAt(20, 42);
         assertTrue(block512.hasFreeSectors());
         assertEquals(3, block512.getUsedSectors(false));
-        
+
         // Allocate all
-        for (int i=0; i<b512.getBATEntriesPerBlock(); i++) {
+        for (int i = 0; i < b512.getBATEntriesPerBlock(); i++) {
             block512.setValueAt(i, 82);
         }
         // Check
         assertFalse(block512.hasFreeSectors());
         assertEquals(128, block512.getUsedSectors(false));
         assertEquals(127, block512.getUsedSectors(true));
-        
+
         // Release one
         block512.setValueAt(10, POIFSConstants.UNUSED_BLOCK);
         assertTrue(block512.hasFreeSectors());
         assertEquals(127, block512.getUsedSectors(false));
         assertEquals(126, block512.getUsedSectors(true));
-        
-        
+
+
         // Now repeat with 4096 block sizes
         BATBlock block4096 = BATBlock.createEmptyBATBlock(b4096, false);
         assertTrue(block4096.hasFreeSectors());
         assertEquals(0, block4096.getUsedSectors(false));
-        
+
         block4096.setValueAt(0, 42);
         block4096.setValueAt(10, 42);
         block4096.setValueAt(20, 42);
         assertTrue(block4096.hasFreeSectors());
         assertEquals(3, block4096.getUsedSectors(false));
-        
+
         // Allocate all
-        for (int i=0; i<b4096.getBATEntriesPerBlock(); i++) {
+        for (int i = 0; i < b4096.getBATEntriesPerBlock(); i++) {
             block4096.setValueAt(i, 82);
         }
         // Check
@@ -177,114 +177,175 @@ public final class TestBATBlock {
     }
 
     @Test
+    public void testOccupiedSize() {
+        POIFSBigBlockSize b512 = POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS;
+        POIFSBigBlockSize b4096 = POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS;
+
+        // Try first with 512 block sizes, which can hold 128 entries
+        BATBlock block512 = BATBlock.createEmptyBATBlock(b512, false);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(0, block512.getUsedSectors(false));
+
+        // Allocate a few
+        block512.setValueAt(0, 42);
+        block512.setValueAt(10, 42);
+        block512.setValueAt(20, 42);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(21, block512.getOccupiedSize());
+
+        // Release one in the middle should not lower size
+        block512.setValueAt(10, POIFSConstants.UNUSED_BLOCK);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(21, block512.getOccupiedSize());
+
+        // Release the last one should lower the size
+        block512.setValueAt(20, POIFSConstants.UNUSED_BLOCK);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(1, block512.getOccupiedSize());
+
+        // Release first one should lower the size
+        block512.setValueAt(0, POIFSConstants.UNUSED_BLOCK);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(0, block512.getOccupiedSize());
+
+        // Set the last one
+        block512.setValueAt(127, 42);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(128, block512.getOccupiedSize());
+
+        block512.setValueAt(126, 42);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(128, block512.getOccupiedSize());
+
+        block512.setValueAt(127, POIFSConstants.UNUSED_BLOCK);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(127, block512.getOccupiedSize());
+
+        // Allocate all
+        for (int i = 0; i < b512.getBATEntriesPerBlock(); i++) {
+            block512.setValueAt(i, 82);
+        }
+        // Check
+        assertFalse(block512.hasFreeSectors());
+        assertEquals(128, block512.getOccupiedSize());
+
+        // Release some in the beginning should not lower size
+        block512.setValueAt(0, POIFSConstants.UNUSED_BLOCK);
+        block512.setValueAt(1, POIFSConstants.UNUSED_BLOCK);
+        block512.setValueAt(13, POIFSConstants.UNUSED_BLOCK);
+        assertTrue(block512.hasFreeSectors());
+        assertEquals(128, block512.getOccupiedSize());
+    }
+
+    @Test
     public void testGetBATBlockAndIndex() {
-       HeaderBlock header = new HeaderBlock(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS);
-       List<BATBlock> blocks = new ArrayList<>();
-       int offset;
-       
-       
-       // First, try a one BAT block file
-       header.setBATCount(1);
-       blocks.add(
-             BATBlock.createBATBlock(header.getBigBlockSize(), ByteBuffer.allocate(512))
-       );
-       
-       offset = 0;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 1;
-       assertEquals(1, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 127;
-       assertEquals(127, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       
-       // Now go for one with multiple BAT blocks
-       header.setBATCount(2);
-       blocks.add(
-             BATBlock.createBATBlock(header.getBigBlockSize(), ByteBuffer.allocate(512))
-       );
-       
-       offset = 0;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 127;
-       assertEquals(127, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 128;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(1, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 129;
-       assertEquals(1, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(1, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       
-       // The XBAT count makes no difference, as we flatten in memory
-       header.setBATCount(1);
-       header.setXBATCount(1);
-       offset = 0;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 126;
-       assertEquals(126, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 127;
-       assertEquals(127, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 128;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(1, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 129;
-       assertEquals(1, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(1, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       
-       // Check with the bigger block size too
-       header = new HeaderBlock(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS);
-       
-       offset = 0;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 1022;
-       assertEquals(1022, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 1023;
-       assertEquals(1023, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 1024;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(1, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-
-       // Biggr block size, back to real BATs
-       header.setBATCount(2);
-       
-       offset = 0;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 1022;
-       assertEquals(1022, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 1023;
-       assertEquals(1023, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(0, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
-       
-       offset = 1024;
-       assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
-       assertEquals(1, blocks.indexOf( BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock() ));
+        HeaderBlock header = new HeaderBlock(POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS);
+        List<BATBlock> blocks = new ArrayList<>();
+        int offset;
+
+
+        // First, try a one BAT block file
+        header.setBATCount(1);
+        blocks.add(
+                BATBlock.createBATBlock(header.getBigBlockSize(), ByteBuffer.allocate(512))
+        );
+
+        offset = 0;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 1;
+        assertEquals(1, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 127;
+        assertEquals(127, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+
+        // Now go for one with multiple BAT blocks
+        header.setBATCount(2);
+        blocks.add(
+                BATBlock.createBATBlock(header.getBigBlockSize(), ByteBuffer.allocate(512))
+        );
+
+        offset = 0;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 127;
+        assertEquals(127, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 128;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(1, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 129;
+        assertEquals(1, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(1, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+
+        // The XBAT count makes no difference, as we flatten in memory
+        header.setBATCount(1);
+        header.setXBATCount(1);
+        offset = 0;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 126;
+        assertEquals(126, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 127;
+        assertEquals(127, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 128;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(1, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 129;
+        assertEquals(1, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(1, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+
+        // Check with the bigger block size too
+        header = new HeaderBlock(POIFSConstants.LARGER_BIG_BLOCK_SIZE_DETAILS);
+
+        offset = 0;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 1022;
+        assertEquals(1022, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 1023;
+        assertEquals(1023, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 1024;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(1, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        // Biggr block size, back to real BATs
+        header.setBATCount(2);
+
+        offset = 0;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 1022;
+        assertEquals(1022, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 1023;
+        assertEquals(1023, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(0, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
+
+        offset = 1024;
+        assertEquals(0, BATBlock.getBATBlockAndIndex(offset, header, blocks).getIndex());
+        assertEquals(1, blocks.indexOf(BATBlock.getBATBlockAndIndex(offset, header, blocks).getBlock()));
     }
 }